The Complete Solidity Course - Zero to Advanced for Blockchain and Smart Contracts - Mapping in Solidity

The video tutorial explains mapping in Solidity, highlighting its simplicity compared to Python or JavaScript. It covers creating a map with keys and values, adding and retrieving data, and removing data. The tutorial also discusses default values in mapping and concludes with key points to remember.

What is the primary purpose of mapping in Solidity?

• To create a list of items

• To store data in key-value pairs

• To perform mathematical operations

• To iterate over data structures

What is a key difference between mappings in Solidity and arrays?

• Mappings can be resized dynamically

• Mappings do not allow iteration

• Mappings can store only integers

• Mappings can store only strings

In Solidity, what can be used as a key in a mapping?

• Only integers

• Only strings

• Any data type

• Only addresses

Which of the following is true about the keys in a Solidity mapping?

• They must be unique

• They can be of any data type

• They can be duplicated

• They are automatically sorted

What is the function of the 'set address' function in a mapping?

• To iterate over all addresses in the mapping

• To delete an address from the mapping

• To retrieve the value of an address

• To add an address with a value to the mapping

What is the purpose of the 'get address' function in a mapping?

• To retrieve the value associated with an address

• To remove an address

• To add a new address

• To update the value of an address

What happens when you try to access a non-existent key in a Solidity mapping?

• It returns a default value of zero

• It returns undefined

• It returns the last added value

• It throws an error

How can you remove an entry from a mapping in Solidity?

• By setting its value to null

• By using the delete method

• By overwriting it with a new value

• By using a special remove function

What is the default return value when accessing a non-existent key in a mapping?

• Null

• Undefined

• Negative one

• Zero

What is demonstrated in the practical section of the video?

• How to use mappings in Python

• How to create a new mapping

• How to set, get, and remove entries in a mapping

• How to iterate over a mapping